The present application claims priority to Italian Patent Application Ser. No. MI 2000A 002481, filed Nov. 17, 2000.
The present invention relates to flat cards in which the fibre material in a thin layer is processed by a series of surfaces facing one another, in relative motion and equipped with a card clothing formed by a plurality of pins of given shapes, inclinations, and rigidities, between which the fibre material is exchanged, opened, spread, and cleaned, so eliminating the majority of the particles of residual dirt, waste and tangles or neps. In this operation, the fibres form between them a mixture or blend, and a ribbon of non-twisted fibres is formed as a web to be condensed and sent on to the subsequent processing stages.
In its broadest lines, the operation of carding of a cotton type is performed according to the diagram illustrated in FIG. 1. The raw material 1 is made up of fibre staple and is accumulated in the end part 2 of a storage bin. From the bottom of the storage bin, a system of discharging cylinders or lobed rollers 3 rotating at a controlled speed discharges, onto a chute 4, the fibres in the form of a mat 5, feeding them to the card. The latter machine is provided with a feed roller 6 which presses and controls the mat against the feed board 7 and supplies a wisp or bundle of the mat to the taker-in roller 8, which is also commonly referred to as xe2x80x9clicker-in rollerxe2x80x9d or simply xe2x80x9clicker-inxe2x80x9d, currently also xe2x80x9cbriseurxe2x80x9d. The said licker-in is provided with a clothing of pins and turns at a considerable speed of rotation. The fibres fed to the licker-in are roughly combed and distributed in a layer thinner than the original layer 5 arriving from the chute 4. Throughout its rotation, illustrated in FIG. 1 in the counter-clockwise direction, the layer of fibres encounters one or more opening and purification devices consisting of clothed segments and knives for removing any impurities that may be present, the said impurities then being sucked in by suction mouths and thus carried away.
Set downstream of the licker-in is the main carding drum 10. Generally speaking, the said main carding drum 10 is operated at a linear speed that is higher than the speed of the licker-in 8. The pins of the clothing of the main carding drum 10 thus remove the fibres from the licker-in in positions corresponding to the closest generatrices between the two cylinders. Located around and on the outside of the main rotating carding drum 10 and downstream of the feed system with licker-in rollers are the carding flats, which, according to the particular type of card, are of the fixed type 11, the mobile type 12, or finally the rotating type, the latter not being illustrated in the figure for reasons of simplicity. The said flats are set around the main drum for carding the fibres fed by the licker-in rollers, the said fibres, after passing over the main carding drum, being then discharged by the card downstream of the flats by discharging cylinders 13 and doffing cylinders 14.
According to the Italian patent No. 1 296 452 in the name of the same applicant, in order to obtain a better effect of cleaning and blending, the fibres fed into the card are divided between a plurality of taker-in rollers or licker-in rollers, which operate in parallel to process the fibres and then feed them to the main carding drum in different points of its circumference.
One of the advantages of the above technical solution lies in the greater effect of cleanliness and quality of the fibres coming out of the licker-in rollers due to the small thickness of the layer of fibres processed on the clothing of each licker-in. The said layer exerts, in fact, an action of retention of the particles of dirt that are found inside the layer according to the thickness of the latter: the thinner the layer, the greater the degree of cleaning.
According to an embodiment illustrated in FIG. 3 of the above-mentioned prior patent, various batches of fibres are processed, and the licker-in rollers are made to work in parallel. For this purpose, the licker-in rollers are each equipped with components and with an actuating system for operating in conditions such that they are independent of one another. Each of the licker-in rollers is driven at the desired speed and fed with bundles of fibres at the desired rate, in order to obtain the correct blending and the desired quality.
According to the type and quality of the fibres to which it is dedicated, each of the two licker-in rollers is equipped with a clothing made to measure which may be more or less aggressive, so as to obtain a higher degree of opening and cleaning of the fibres, thus limiting possible breaking of the fibres and the formation of neps. In this way, a greater efficiency and longer working life of the clothing is obtained according to the fibre on which it is designed to work.
The same arrangement is adopted for the type, number and adjustment of the components of the auxiliary elements for purifying the fibres, the equipment being basically made up of clothed segments, knives and suction mouths, again according to the type and quality of the fibres for which each of the licker-in rollers is designed. One of the consequences of the conformation of the above feed device is the delivery of the two batches of fibres at different points of the main carding drum and the stratification of the materials one on top of the other according to the reverse order of delivery onto the clothing of the main carding drum. The different position of the fibre material with respect to the asperities of the clothing gives rise to a more or less aggressive processing performed on the fibres of the two batches according to the order of their stratification.
The present invention more in particular relates to a multiple-feed card scheme with a plurality of licker-in rollers or briseur working in parallel to improve processing of the fibres fed to the card as regards their cleaning, spreading and the effect of blending of the fibres processed during carding when the batches of fibres that are fed in present substantial differences between them in their characteristics and/or behaviour.
The above-mentioned scheme is defined as a flat card in which the main card drum (10) is fed with a number of batches of fibers (A, B, . . . , H, L) by means of a plurality of feed devices (2OA, . . . , 20L) comprising taker-in rollers or licker-in rollers (8A, . . . , 8L), which operate in parallel to feed, upstream of the moving flats and in different points of the main carding drum (10), the fibers which they have already roughly spread and purified in a layer that adheres to the clothing of each licker-in roller (8A, . . . , 8L), characterized in that the feed points with the various licker-in rollers (8A, . . . , 8L) are set in sequence and staggered according to angles (xcex1AB, . . . , xcex1HL) for an overall arc of circle of amplitude (xcex1AB, . . . , xcex1FL), in such a way as to constitute a series of pre-carding areas that are specific for each batch fed in according to the succession of batches of fibers (A, . . . , L), and in that each licker-in and each pre-carding area is provided with equipment that can be specifically regulated and adapted for each batch of fibers that is being processed.